Solid Freeform Fabrication (SFF) processes are generally processes in which objects are constructed utilizing a computer model of the objects. These processes are used in various fields, such as design-related fields for purposes of visualization, demonstration and mechanical prototyping.
Various techniques of Solid Freeform Fabrication exist, one such technique being three-dimensional (3-D) printing. 3-D printing, as opposed to 2-D printing, generally involves the dispensing of layers of building material, one on top of the other, in order to construct objects. In one such 3-D printing technique, building materials are dispensed in layers from a printing head having a set of nozzles. Depending on the building materials, the layers are then cured using a suitable curing device. The building materials may include modeling materials and support materials, which form the object and the support constructions supporting the object as it is being built.
In cases where objects include overhanging features or shapes, voids, and so on, objects are typically constructed using support constructions, which are used during the printing but are subsequently removed in order to reveal the final shape of the object fabricated. Of course, the use of support materials and formation of support constructions necessitates additional materials, printing time, curing time, cleaning and so on.
Using another method of object printing, objects can be fabricated substantially without support material. Such a method may utilize an apparatus for manufacturing a three-dimensional object by solidifying in layers a liquid material which can be solidified under the influence of light, at locations corresponding to cross-sections of the object. The method requires depositing layers of substantially liquid content, and then selectively curing the layers according to a required layer cross-section, e.g. by curing a cross-section at the surface of a liquid filled vat. Such approach, however, enables using only a single building material for fabricating the object.
It would be advantageous to have an SFF system which enables fabrication of an object comprising a plurality of materials, while at the same time requiring minimal or no support for fabricating 3-D objects for the fabrication process.